Urethane pads used for seats mounted on conveyances, such as vehicles, boats, ships, and aircraft, furniture chairs, and the like may give users a sense of lateral wobble. For example, an urethane pad mounted on a vehicle may be deformed by vibrations in a low-frequency band (for example, about 1 Hz) input when the vehicle goes around a mild curve or makes a lane change, resulting in production of a sense of wobble, such as sideslip or lateral rocking about a roll axis. Such a sense of wobble is a factor affecting the steering stability. There is a technique, for reducing the sense of wobble, in which tan 8 with respect to vibrations in a low-frequency band is set in a predetermined range (Patent Literature 1).